Magnetic Field Assisted Deposition

ABSTRACT

Embodiments relate to applying a magnetic field across the paths of injected polar precursor molecules to cause spiral movement of the precursor molecules relative to the surface of a substrate. When the polar precursor molecules arrive at the surface of the substrate, the polar precursor molecules make lateral movements on the surface due to their inertia. Such lateral movements of the polar precursor molecules increase the chance that the molecules would find and settle at sites (e.g., nucleation sites, broken bonds and stepped surface locations) or react on the surface of the substrate. Due to the increased chance of absorption or reaction of the polar precursor molecules, the injection time or injection iterations may be reduced.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.13/410,545 filed on Mar. 2, 2012, which claims priority under 35 U.S.C.§119(e) to U.S. Provisional Patent Application No. 61/470,405 filed onMar. 31, 2011, which are incorporated by reference herein in theirentirety.

BACKGROUND

1. Field of Art

The present invention relates to using a magnetic field for depositingone or more layers of materials on a substrate.

2. Description of the Related Art

Various chemical processes are used to deposit material on a substrate.Such chemical processes include chemical vapor deposition (CVD), atomiclayer deposition (ALD) and molecular layer deposition (MLD). CVD is themost common method for depositing a layer of material on a substrate. InCVD, reactive gas precursors are mixed and then delivered to a reactionchamber where a layer of material is deposited after the mixed gas comesinto contact with the substrate.

ALD is another way of depositing material on a substrate. ALD uses thebonding force of a chemisorbed molecule that is different from thebonding force of a physisorbed molecule. In ALD, source precursor isabsorbed into the surface of a substrate and then purged with an inertgas. As a result, physisorbed molecules of the source precursor (bondedby the Van der Waals force) are desorbed from the substrate. However,chemisorbed molecules of the source precursor are covalently bonded, andhence, these molecules are strongly adsorbed in the substrate and notdesorbed from the substrate. The chemisorbed molecules of the sourceprecursor (adsorbed on the substrate) react with and/or are replaced bymolecules of reactant precursor. Then, the excessive precursor orphysisorbed molecules are removed by injecting the purge gas and/orpumping the chamber, obtaining a final atomic layer.

MLD is a thin film deposition method similar to ALD but in MLD,molecules are deposited onto the substrate as a unit to form polymericfilms on a substrate. In MLD, a molecular fragment is deposited duringeach reaction cycle. The precursors for MLD have typically beenhomobifunctional reactants. MLD method is used generally for growingorganic polymers such as polyamides on the substrate. The precursors forMLD and ALD may also be used to grow hybrid organic-inorganic polymerssuch as Alucone (i.e., aluminum alkoxide polymer havingcarbon-containing backbones obtained by reacting trimethylaluminum (TMA:Al(CH₃)₃) and ethylene glycol) or Zircone (hybrid organic-inorganicsystems based on the reaction between zirconium precursor (such aszirconium t-butoxide Zr[OC(CH₃)₃)]₄, or tetrakis(dimethylamido)zieconiumZr[N(CH₃)₂]₄) with diol (such as ethylene glycol)).

In such deposition processes, molecules are absorbed on the surface ofthe substrate, react with material on the surface or replace material onthe surface. Depending on the substrate and/or the type of precursor,however, the precursor molecules are not easily absorbed on the surfaceof the substrate. Alternatively, the precursor molecules may not easilyreact with or replace material on the surface of the substrate. In suchcases, the injection time of the precursor is increased or the processof injecting the precursor is repeated for a number of times to ensurethat a sufficient amount of precursor molecules are absorbed in thesurface of the substrate. The increased time or repetition of processresults in lower efficiency and increased time for depositing materialson the substrate.

SUMMARY

Embodiments relate to a method of depositing a layer of material on asubstrate where injected precursor molecules are subject to a magneticfield that traverses the paths of the precursor molecules to thesubstrate. The injected precursor molecules are polar precursormolecules. Hence, the magnetic field causes spiral movements of theprecursor molecules relative to a surface of the substrate as theprecursor molecules move toward the substrate. The surface of thesubstrate is exposed to the precursor molecules that move along thespiral paths. Such spiral movements of the precursor moleculesfacilitate absorption or reaction of the precursor molecules with thesurface of the substrate.

In one embodiment, excess precursor molecules remaining after exposingthe surface of the substrate to the injected precursor molecules aredischarged from an apparatus for performing the deposition process.

In one embodiment, radicals are generated as precursor molecules byapplying voltage across electrodes.

In one embodiment, the substrate is moved relative to a reactor thatinjects the precursor molecules onto the surface of the substrate.

In one embodiment, the magnetic field is generated by permanent magnetsor electromagnets.

In one embodiment, the precursor molecules are source precursormolecules or reactant precursor molecules for performing atomic layerdeposition (ALD), chemical vapor deposition (CVD) or molecular layerdeposition (MLD) on the substrate.

In one embodiment, the precursor molecules are methylsilane molecules,dimethylaluminumhydride (DMAH) molecules or dimethylethylamine alane(DMEAA) molecules.

Embodiments relate to an apparatus for depositing a layer of material ona substrate. The apparatus may include a body and a plurality of magnetswithin or outside the body. The body is formed with a reaction chamberin which injected precursor molecules travel to come in contact with thesurface of the substrate. The magnets are configured to generate amagnetic field within the reaction chamber. The magnetic field traversespaths of the precursor molecules to the substrate to cause spiralmovements of the precursor molecules relative to a surface of thesubstrate.

In one embodiment, the apparatus further includes a mechanism coupled tothe substrate of the body to cause a relative motion between the bodyand the substrate.

In one embodiment, the body is further formed with a channel forsupplying the precursor molecules to the reaction chamber, aconstriction zone connected to the reaction chamber and having a heightlower than the reaction chamber, and an exhaust portion connected to theconstriction zone and configured to discharge excess precursor moleculesfrom the apparatus.

In one embodiment, at least one of the magnets forms a wall of thereaction chamber.

In one embodiment, at least one of the magnets is placed outside thebody.

In one embodiment, the body is formed of a non-magnetic material.

In one embodiment, one of the plurality of magnet is placed at one sideof the reaction chamber and another of the plurality of magnet is placedat an opposite side of the reaction chamber.

In one embodiment, the apparatus further includes an electrode extendingalong a plasma chamber formed in the body. The plasma is generatedwithin the plasma chamber by applying voltage across the electrode andthe body.

In one embodiment, the body is further formed with a channel forsupplying gas into the plasma chamber, perforations between the reactorchamber and the plasma chamber, a constriction zone connected to thereaction chamber and having a height lower than the reaction chamber,and an exhaust portion connected to the constriction zone and configuredto discharge excess precursor molecules from the apparatus.

In one embodiment, the plurality of magnets are permanent magnets orelectromagnets.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross sectional diagram of a linear deposition device,according to one embodiment.

FIG. 2 is a perspective view of a linear deposition device, according toone embodiment.

FIG. 3 is a perspective view of a rotating deposition device, accordingto one embodiment.

FIG. 4A is a diagram illustrating an injector with magnets attachedthereto, according to one embodiment.

FIG. 4B is a sectional diagram of the injector of FIG. 4A taken alongline A-B, according to one embodiment.

FIG. 5A is a conceptual diagram illustrating paths of precursormolecules traveling to a substrate without application of a magneticfield.

FIG. 5B is a conceptual diagram illustrating paths of precursormolecules traveling to a substrate when a magnetic field is applied,according to one embodiment.

FIG. 6 is a sectional diagram of a set of injectors, according to oneembodiment.

FIG. 7 is a sectional diagram of an injector and a radical reactor,according to one embodiment.

FIG. 8 is a sectional diagram of an injector and a radical reactor,according to another embodiment.

FIG. 9 is a sectional diagram of an injector and a radical reactor,according to another embodiment.

FIG. 10 is a flowchart illustrating a process of injecting precursoronto the substrate, according to one embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments are described herein with reference to the accompanyingdrawings. Principles disclosed herein may, however, be embodied in manydifferent forms and should not be construed as being limited to theembodiments set forth herein. In the description, details of well-knownfeatures and techniques may be omitted to avoid unnecessarily obscuringthe features of the embodiments.

In the drawings, like reference numerals in the drawings denote likeelements. The shape, size and regions, and the like, of the drawing maybe exaggerated for clarity.

Embodiments relate to applying a magnetic field across the paths ofinjected polar precursor molecules to cause spiral movements of theprecursor molecules relative to the surface of a substrate. When thepolar precursor molecules arrive at the surface of the substrate, thepolar precursor molecules make movements parallel to the surface of thesubstrate due to their inertia. Such lateral movements of the polarprecursor molecules increase the chance that the molecules would attachor react on certain sites on the substrate (e.g., nucleation sites,broken bonds and stepped surface locations). Due to the increased chanceof absorption or reaction of the polar precursor molecules, theinjection time or injection iterations may be reduced.

Polar precursor describe herein refers to material including moleculesor their chemical groups having an electric dipole or multipole moment.Polarity is dependent on the difference in electronegativity betweenatoms in a compound and the symmetry of the compound's structure. Polarprecursor may include, among others, linear molecules (e.g., CO),molecules with a single H (e.g., HF), molecules with an OH at one end(e.g., CH₃OH and C₂H₅OH), molecules with an O at one end (e.g., H₂O),molecules with an N at one end (e.g., NH₃) and plasma. Polar precursoralso includes materials such as Methylsilane ((CH₃)_(x)Si_(4-x), wherex=1, 2 or 3), dimethylaluminumhydride (DMAH) and dimethylethylaminealane (DMEAA).

In contrast, non-polar precursor includes molecules that have nopolarity in the bonds or have symmetrical arrangement of polar bonds.Non-polar precursor includes, among others, diatomic molecules of thesame element (e.g., O₂, H₂, N₂), most carbon compounds (e.g., CO₂, CH₄,C₂H₄) and noble or inert gases (e.g., He and Ar).

Example Apparatuses for Depositing Material

FIG. 1 is a cross sectional diagram of a linear deposition device 100,according to one embodiment. FIG. 2 is a perspective view of the lineardeposition device 100 (without chamber walls to facilitate explanation),according to one embodiment. The linear deposition device 100 mayinclude, among other components, a support pillar 118, the processchamber 110 and one or more reactors 136. The reactors 136 may includeone or more of injectors and radical reactors. Each of the injectorsinjects source precursors, reactant precursors, purge gases or acombination of these materials onto the substrate 120. The lineardeposition device 100 may perform chemical vapor deposition (CVD),atomic layer deposition (ALD), molecular layer deposition (MLD) or acombination thereof.

The process chamber enclosed by the walls may be maintained in a vacuumstate to prevent contaminants from affecting the deposition process. Theprocess chamber 110 contains a susceptor 128 which receives a substrate120. The susceptor 128 is placed on a support plate 124 for a slidingmovement. The support plate 124 may include a temperature controller(e.g., a heater or a cooler) to control the temperature of the substrate120. The linear deposition device 100 may also include lift pins thatfacilitate loading of the substrate 120 onto the susceptor 128 ordismounting of the substrate 120 from the susceptor 128.

In one embodiment, the susceptor 128 is secured to brackets 210 thatmove across an extended bar 138 with screws formed thereon. The brackets210 have corresponding screws formed in their holes for receiving theextended bar 138. The extended bar 138 is secured to a spindle of amotor 114, and hence, the extended bar 138 rotates as the spindle of themotor 114 rotates. The rotation of the extended bar 138 causes thebrackets 210 (and therefore the susceptor 128) to make a linear movementon the support plate 124. By controlling the speed and rotationdirection of the motor 114, the speed and direction of the linearmovement of the susceptor 128 can be controlled. The use of a motor 114and the extended bar 138 is merely an example of a mechanism for movingthe susceptor 128. Various other ways of moving the susceptor 128 (e.g.,use of gears and pinion at the bottom, top or side of the susceptor128). Moreover, instead of moving the susceptor 128, the susceptor 128may remain stationary and the reactors 136 may be moved.

FIG. 3 is a perspective view of a rotating deposition device 300,according to one embodiment. Instead of using the linear depositiondevice 100 of FIG. 1, the rotating deposition device 300 may be used toperform the deposition process according to another embodiment. Therotating deposition device 300 may include, among other components,reactors 320, 334, 364, 368, a susceptor 318, and a container 324enclosing these components. The susceptor 318 secures the substrates 314in place. The reactors 320, 334, 364, 368 are placed above thesubstrates 314 and the susceptor 318. Either the susceptor 318 or thereactors 320, 334, 364, 368 rotate to subject the substrates 314 todifferent processes.

One or more of the reactors 320, 334, 364, 368 are connected to gaspipes (not shown) to provide source precursor, reactor precursor, purgegas and/or other materials. The materials provided by the gas pipes maybe (i) injected onto the substrate 314 directly by the reactors 320,334, 364, 368, (ii) after mixing in a chamber inside the reactors 320,334, 364, 368, or (iii) after conversion into radicals by plasmagenerated within the reactors 320, 334, 364, 368. After the materialsare injected onto the substrate 314, the redundant materials may beexhausted through outlets 330, 338.

Embodiments as described herein may be use in the linear depositiondevice 100, the rotating deposition device 300 or other types ofdeposition device. Taking the examples of the linear deposition device100 and the rotating deposition device 300, the substrate 120 (or 314)may undergo different sequences of processes by moving the substrate 120(or 314) relative to the reactors in one direction and then in anopposite direction.

Example Reactor with Magnetic Field Generated Therein

FIG. 4A is a perspective view of an injector 136 according to oneembodiment. The injector 136 includes, among other components, a set ofmagnet 424A, 424B to generate a magnetic field in the injector 136. Themagnetic field in the injector 136 causes polar precursor molecules tomove along spiral paths to the surface of the substrate 120, asdescribed below in detail with reference to FIG. 5B.

The injector 136 has a body 404 that is connected to a supply pipe 410and a discharge pipe 420. The supply pipe 410 receives source precursor,reactant precursor, mixed gas compound, purge gas or a combinationthereof. Excess precursor molecules and/or by-product gas are dischargedfrom the injector 136 via the discharge pipe 420.

The injector 136 injects the received gas onto the surface of thesubstrate 120 as the substrate 120 moves in a direction indicated byarrow 450 to deposit a layer 140 of material on the substrate 120. In analternative embodiment, the injector 136 may move relative to a fixedsubstrate 120. Subsequently, the substrate 120 may be injected with adifferent material using the same or different injector or radicalreactor.

In one embodiment, the body 404 is formed of non-magnetic materials suchas Aluminum. When the injector 136 is used in a higher temperaturerange, it is advantageous to form the body 404 of Al₂O₃, AlN or ceramicsuch as SiC.

FIG. 4B is a sectional diagram of the injector 136 of FIG. 4A takenalong line A-B, according to one embodiment. The body of the injector136 is formed with a channel 462, perforations 464 (e.g., holes orslits), a reactor chamber 468, a constriction zone 470 and an exhaustportion 472. The supply pipe 410 is connected to the channel 462 tosupply precursor material into the reaction chamber 468 via theperforations 464. The precursor material comes into contact with thesubstrate 120 below the reaction chamber 468.

After part of the precursor material is absorbed onto the surface of thesubstrate 120, the remaining precursor material (i.e., excess precursormolecules) and/or by-product gases pass through the constriction zone470 and are discharged out of the injector 136 via the exhaust portion472 that is connected to the pipe 420.

The constriction zone 470 has a height H₂ lower than the height H₁ ofthe reaction chamber 468. Hence, the flow rate of the precursor materialis higher in the constriction zone 470 compared to the reaction chamber468. The higher flow rate in the reaction chamber 468 enables theremoval of physisorbed precursor molecules from the surface of thesubstrate 120 while retaining the chemisorbed precursor molecules on thesubstrate 120.

The set of magnets 424A, 424B generates a magnetic field generally in adirection perpendicular to the flow direction of the precursormolecules. That is, the set of magnets 424A, 424B generates a magneticfield generally parallel to the surface of the substrate 120. If theprecursor molecules are polar, the magnetic field exerts lateral forceon the precursor molecules, causing the precursor molecules to makespiral movements as the molecules move towards the substrate 120.

After the precursor molecules reach the surface of the substrate 120,the precursor molecules continue to make movements parallel to thesurface of the substrate 120 due to their inertia. Such movements areadvantageous, among other reasons, because the precursor molecules aremore likely to find spots on the substrate 120 amenable to attachment orreaction. Spots amenable for attachment of the precursor moleculesinclude, among others, nucleation sites, broken bonds or stepped regionon the substrate 120. Hence, applying the magnetic field in the injector136 facilitates the absorption or reaction of the precursor molecules onthe substrate 120.

Generation of Magnetic Field

FIG. 5A is a conceptual diagram illustrating paths 514 of precursormolecules 510 traveling to the substrate 120 without application of amagnetic field. Without any magnetic field, the paths 514 are generallylinear from an injection point (i.e., the perforation 464) to thesubstrate 120. Since the motion vectors of the precursor molecules 510have no element parallel to the surface of the substrate 120, theprecursor molecules 510 either becomes absorbed or react at the spotswhere the molecules 510 reaches the substrate 120 or the precursormolecules 510 bounce off from the surface of the substrate 120 withoutor after making minimal lateral movements (i.e., movement parallel tothe surface of the substrate 120) on the substrate 120.

FIG. 5B is a conceptual diagram illustrating paths 518, 522 of precursormolecules 510 traveling to the substrate 120 when magnetic field isapplied in the injector 136, according to one embodiment. When polarprecursor is used, the molecules are subject to Lorentz force as themolecules pass the magnetic field. Assuming that the direction of themagnetic field is from the left to the right as illustrated in FIG. 5B,Lorentz force applied to the molecules is perpendicular to the directionof the magnetic field and the moving direction of the molecules as shownby arrow 526.

Hence, the precursor molecules 510 come to move along spiral paths 522as they move across the magnetic field until the precursor molecules 510reach the surface of the substrate 120. After reaching the surface ofthe substrate 120, the precursor molecules may continue to makemovements parallel to the surface of the substrate 120 before bouncingoff the surface of the substrate 120. The lateral movements of theprecursor molecules 510 on the surface of the substrate 120 tend to belonger compared to cases where the precursor molecules 510 are notapplied with a magnetic field.

During the movements of the precursor molecules 510 parallel to thesurface of the substrate 120, the precursor molecules 510 may reachspots on the surface of the substrate 120 where the precursor molecules510 are more likely to become attached or react with materials on thesurface of the substrate 120. The increased absorption or reaction ofthe precursor molecules 510 contributes to more even absorption of theprecursor molecules 510 on the substrate, increased density of the layerformed on the substrate 120, and reduced number of pin-holes or otherdefects in the deposited layer.

The magnetic field can be formed by magnets of various configurationsand structures. Permanent magnets or electromagnets may be placed withinor outside the reaction chamber of the injector or radical reactor togenerate the magnetic field. The permanent magnets may be made of, forexample, Alnico, Neodymium or Sm-cobalt.

Preferably, a set of magnets are placed at opposite sides of thereaction chamber so that the reaction chamber is subject to a magneticfield that is generally perpendicular to the movement of the precursormolecules. That is, although primary embodiments described herein useinjectors or radical reactors that inject the precursor materialsvertically down towards the substrate, in other embodiments, theprecursor molecules may travel horizontally or in other directions.Regardless of the direction that the precursor molecules travel in suchembodiments, the magnets are placed so that the magnetic field traversesthe travel path of the precursor molecules to cause spiral movements inthe precursor molecules before reaching the substrate.

Further, although it is advantageous that the direction of the magneticfield is perpendicular to the general paths of the precursor moleculesto apply increased Lorentz force, the direction of the magnetic fieldmay be somewhat slanted or non-perpendicular, for example, as describedbelow in detail with reference to FIG. 9.

Alternative Embodiments

FIG. 6 is a sectional diagram of a set of injectors 136A, 136B placed intandem, according to one embodiment. Each of the injectors 136A, 136Bhas a structure and configuration that are the same as the injector 136of FIGS. 4A and 4B except that two injectors are placed in tandem toinject different precursor materials onto the substrate 120.

In one embodiment, the injectors 136A, 136B are used for performingatomic layer deposition (ALD) of Al₂O₃ film. The substrate 120 movesfrom the left to the right and is injected with DMAH as a sourceprecursor by the injector 136A and then injected with O₃ or H₂O as areactant precursor by the injector 136B. DMAH, O₃ and H₂O are polarprecursors, and therefore, these precursors are subject to Lorentz forcecaused by magnets 424A, 424B and magnets 620A, 620B.

In another embodiment, the injectors 136A, 136B are used to deposit AlNfilm by ALD. For this purpose, the substrate 120 moves from the left tothe right and is injected with DMAH as a source precursor by theinjector 136A and then injected with NH₃ as a reactant precursor by theinjector 136B. DMAH and NH₃ are polar precursors, and therefore, theseprecursors are subject to Lorentz force caused by magnets 424A, 424B andmagnets 620A, 620B.

FIG. 7 is a sectional diagram of the injector 136C and a radical reactor136D, according to one embodiment. The injector 136C is substantiallythe same as the injector 136 of FIGS. 4A and 4B except that magnet 702Aforms part of the wall defining a reaction chamber 704 and magnet 702Bforms part of the wall defining an exhaust portion 706. The function ofthe reaction chamber 704 and the exhaust portion 706 are substantiallyidentical to the functions of the reaction chamber 468 and the exhaustportion 472 of FIG. 4B.

The radical reactor 136D generates radicals by applying voltage acrossan inner electrode 722 and an outer electrode 720 (which is part of thebody 712). The body 712 is formed with a channel 710, perforations 714(e.g., holes or slits), a plasma chamber 718, slits 726, a reactionchamber 730, a constriction zone 732 and an exhaust portion 734. Thereaction chamber 730, the constriction zone 732 and the exhaust portion734 have the same function as the reaction chamber 468, the constrictionzone 470 and the exhaust portion 472 of FIG. 4B. A gas or mixture ofgases is injected from a source into the plasma chamber 718 via achannel 710 extending across the length of the radical reactor 136D andthe perforations 714. As the voltage is applied between the innerelectrode 722 and the outer electrode 720, plasma is generated in theplasma chamber 718. As a result, radicals are generated within theplasma chamber 718 and are injected into the reaction chamber 730. Theradicals are generated at a location remote from the substrate 120, andhence, the radical reactor 136D is referred to as a “remote plasmagenerator.”

As the radicals move down towards the substrate 120, the magnetic fieldgenerated by the magnets 744A, 744B causes the radicals to travel alongspiral paths due to Lorentz force. Compared to the case where theradicals are not applied with magnetic field, the radicals travel for alonger distance along the surface of the substrate 120 due to spiralpaths and inertia of the radicals. Hence, the radicals are more likelyto attach to the surface of the substrate 120, or interact/replacesource precursor molecules already absorbed on the surface of thesubstrate 120.

The use of a remote plasma generator is merely an example, and variousother types of plasma generators may also be used to generate and injectradicals onto the substrate 120. Regardless of the structure, the plasmagenerators may include magnets that generate the magnetic field thattraverses across the traveling path of the radicals.

Further, although the radical reactor 136D has the magnets 744A, 744Billustrated as forming part of the wall for the reaction chamber 730 andthe exhaust portion 744B, the magnets may be installed as separateelements attached inside or outside these walls.

In one embodiment, the injector 136C and the radical reactor 136D areused for depositing Al₂O₃ layer on the substrate 120. For this purpose,the substrate 120 moves from the left to the right and is injected withDMAH as a source precursor by the injector 136C and then injected withO* radicals as a reactant precursor by the injector 136D. DMAH and O*radicals are polar precursors, and therefore, these precursors aresubject to Lorentz force caused by magnets 702A, 702B and magnets 744A,744B.

In another embodiment, the injector 136C and the radical reactor 136Dare used for depositing AlN layer on the substrate 120. For thispurpose, the substrate 120 moves from the left to the right and isinjected with DMAH as a source precursor by the injector 136C and theninjected with N* radicals as a reactant precursor by the injector 136D.DMAH and N* radicals are polar precursors, and therefore, theseprecursors are subject to Lorentz force caused by magnets 702A, 702B andmagnets 744A, 744B.

The magnets may also be placed to form walls of the radical chamber.FIG. 8 is a sectional diagram of an injector 136E and a radical reactor136F, according to another embodiment. Magnet 812A forms a wall of areaction chamber 816 of the injector 136E. Similarly, magnet 824A formsa wall of a reaction chamber 820 of the radical reactor 136F. Magnet812B is attached to interior of the reaction chamber 816 and magnet 824Bis attached to the interior of the reaction chamber 820.

The magnets may also have an asymmetric structure. FIG. 9 is a sectionaldiagram of an injector 136G and a radical reactor 136H, according toanother embodiment. In the injector 136G and the radical reactor 136H,the magnets 912A, 912B and the magnets 916A, 916B are asymmetric. Hence,the direction of the magnetic field may be slanted as illustrated inFIG. 9. As long as the magnets are designed to exert Lorentz force onthe precursor molecules, the dimensions, strengths, and theconfiguration of the magnets may be varied.

Method of Performing Deposition Using Magnets

FIG. 10 is a flowchart illustrating a process of injecting precursoronto the substrate, according to one embodiment. First, precursor isinjected 1010 into a reactor chamber of an injector or a radicalreactor. A magnetic field is applied 1020 to the reactor chamber so thatthe magnetic field traverses the paths of precursor molecules travelingto the substrate.

By applying the magnetic field, the precursor molecules are subject toLorentz force. The Lorentz force causes the precursor molecules to takespiral paths to the substrate.

The substrate is then exposed 1030 to the precursor molecules. Due tothe spiral path, the precursor molecules travel along the surface of thesubstrate for a distance before bouncing off the surface. As a result,the precursor molecules are more likely to settle on spots of thesurface of the substrate where the molecules can attach or react.

Excess precursor molecules remaining after exposure of the substrate arethen discharged 1040 from the reactor chamber.

Although the present invention has been described above with respect toseveral embodiments, various modifications can be made within the scopeof the present invention. Accordingly, the disclosure of the presentinvention is intended to be illustrative, but not limiting, of the scopeof the invention, which is set forth in the following claims.

What is claimed is:
 1. An apparatus for depositing a layer on a substrate, comprising: a process chamber; a reactor at least partially enclosed in a process chamber, the reactor comprising electrodes for generating radicals as precursor molecules, the reactor formed with a reaction chamber in which the precursor molecules travel to a surface of the substrate; a plurality of magnets within the processor chamber and attached to the reactor, the plurality of magnets configured to generate a magnetic field within the reaction chamber, the magnetic field traversing paths of the precursor molecules to the substrate to cause spiral movements of the precursor molecules relative to a surface of the substrate; and a mechanism coupled to the substrate of the body to cause relative motion between the body and the substrate.
 2. The apparatus of claim 1, wherein the reactor is further formed with a channel for supplying the precursor molecules to the reaction chamber, a constriction zone connected to the reaction chamber and having a height lower than the reaction chamber, and an exhaust portion connected to the constriction zone and configured to discharge excess precursor molecules from the apparatus.
 3. The apparatus of claim 1, wherein at least one of the magnets form a wall of the reaction chamber.
 4. The apparatus of claim 1, wherein at least one of the magnets are placed outside the body.
 5. The apparatus of claim 1, wherein the reactor is formed of non-magnetic material.
 6. The apparatus of claim 1, wherein one of the plurality of magnet is placed at one side of the reaction chamber and another of the plurality of magnet is placed at an opposite side of the reaction chamber.
 7. The apparatus of claim 1, wherein the reactor is formed with a plasma chamber along which the electrodes extending, and wherein plasma is generated within the plasma chamber by applying voltage across the electrodes.
 8. The apparatus of claim 7, wherein the reactor is further formed with a channel for supplying gas into the plasma chamber, perforations between the reactor chamber and the plasma chamber, a constriction zone connected to the reaction chamber and having a height lower than the reaction chamber, and an exhaust portion connected to the constriction zone and configured to discharge excess precursor molecules from the apparatus.
 9. The apparatus of claim 1, wherein the plurality of magnets are permanent magnets or electromagnets. 